Polypropylene is a general-purpose synthetic rope. It is inexpensive, lightweight, and does not absorb water, which allows the rope to float and makes it particularly useful for marine applications and pools. It has medium stretch characteristics that allow the rope to slowly stretch. Ultraviolet (UV) light inhibitors have been added to prevent degradation. Relative to other synthetic ropes, polypropylene does not hold knots well and has limited abrasion resistance.